Combination power tool



Feb. 4,' 1936. HF LEMEKE COMBINATION POWER TOOL Filed Aug. 6, 1934 2 Sheets-Sheet l Feb. 4, 1936. H. LEMBKE l COMBINATION POWER TOOL 2 sheets-sheet 2 Filled Aug. 6, 1934 INVENTOR d' n .Effclgfofd I/zmbk Y ATTORNEYS Patented Feb. 4,1936

j UNITED lSTATES 1emu-:NT oFFicE 2,029,326 oonrmArIoN rowEa 'roon Halford Lembke, Seattle, Wash. Application August s, 1934, serial No. 138,125

l 11 claims.- (cl. 255-41) My present invention relates to the art of power tobls and more particularly to a combination power tool, which, by virtue. of its unusual construction, is adaptable for several purposes.

My invention is particularly adapted for use with a flexible shaft although there may be many conditions of use under which other drive means may be employed. 'I'he outstanding characteristie of my tool resides in the fact that while the o motive drive is continuous the applied force is dependent upon the application of'pressure by the user in the direction of the tool. This makes it a very useful tool for the carving of wood or stone and the like, in that as the pressure applied by the user is decreased the blow struck by the device is proportionately decreased until it reaches the point where if no pressure is applied no blow is struck. This is of particular value to the workers in wood or stone in that it gives an opportunity to vary the blow from the maximum capacity of the machine to no blow at all. Further, with minor adjustments my4 tool can be used to bore with the ordinary bit of the twist variety or it may be used to drive a rock drill and the construction is suchthat it will, by adjustment, revolve the drill with a step by step motion. One of the outstanding features of my present construction is the fact that the engaging surfaces which in eifect create cam surfaces are formed of hardened steel balls such as normally are referred to as ball-bearings. The temper of these bearings is very satisfactory for the cam operation andshould they become damaged or worn they are easily and cheaply replaceable.

Other and more speciflc objects will be apparent from the following description taken in connection with the accompanying drawings, where- Figure 1 is'a longitudinal sectional view of a tool made after the teachings of my invention, in which the housing and certain other parts are shown in section to better illustrate the interior construction. i

Figure 2 is a view similar to Figure 1 with the cutting plane revolved 90 degrees and the parts shown in greater section.

Figure 3 is a view similar to Figure 1 showing all the various parts in section.

Figure 4 illustrates a fragmentary sectional view of my tool and it is locked into position for use with a rotary drill and showing the manner of using a special clip which holds the cam balls in locked relationship.

'Figure 5 shows my tool with a wood chisel in place together with a flexible shaft and electric motor drive which has been found to be very practical.

Figures 6, 7, 8, 9, 10, 11, 12 and 13 are cross sectional views taken along the correspondingly numbered section lines of Figure 3.

Figure 14 shows in perspective the clip used to 5 retain a revolving drillin operating position in my tool.

Figure 15 illustrates a modied form of back- I ing spacer which is of particular value in the 10 heavier size tools.

Figure 16 is a' cross-sectional view taken along the line lli-I6 of Figure 15.

. Referring to the drawings, throughout which 'like reference characters indicate like parts, I4 15 designates the shell or housing of my device. This contains the mechanism which may be generally classified as the driving mechanism. As viewed in Figure 3 those parts which lie to the right of section line I0 constitute its driving 20 mechanism which is driven by the flexible shaft I6 while those parts lying to the left of section line III-I0 provide the driven mechanism which is adaptable for use as a hammer, rock drill or for use in driving a twist drill. Power is applied 25 to the tool from any convenient source of energy by revolving spindle I6. This spindle has secured to it a ball seat member I 8 and is supported on the anti-friction bearings I9 and 20. In the drawings I vhave illustrated the application of 30 pot-.er as by means of the exible shaft 2| and I have shown the exible shaft terminal 22 as fixedly secured within and coaxially with spindle I6. This of course should be understood as being only one method of applying rotary power. 35

It is conceivable that an electric motor might be directly connected at this point, the shaft of the motor replacing terminal 22 or the device might be mechanically operated, particularly if a battery of the devices were to be used. The 40 ball seat I8 is in effect a face cam and naturally there is considerable thrust when the cam surface is engaged which is taken care of by the thrust bearing 24 and the shock load incidental to the cam operation is absorbed in the larger 45 sizes by the compression spring 26. This compression spring is disposed coaxially with spindle I6 and has oppositely faced seats 28 and 30. In the smaller size tools it has been found unnecessary to employ the cushion spring 26 and 50 in this instance a solid spacer, as 3 I, is employed. This is arranged coaxally upon spindle lli and `has shoulders which abut the inner race of ballbearings I9 and 20, so as to definitely space the two apart. 'This assembly provides a more or less 55 fixed driving end disposed as it is upon the two radial load bearings I9 and 29, and being provided with the thrust bearing 24. As' a further refinement to assure an even contact between the ball surfaces, which act as the cams in my device, I provide that the driven member be provided within ball seat I8 with a rockable ball support member 32. The exact construction will be most easily understood from a study of Figures 2, 3 and 4, in which the rocker member 32 is pivotably secured. by pin 33, suflicient clearance being provided so that the thrust of the cam action is transferred from rocker 32 to the at surface 34 of member I 8.

The driven mechanism which is disposed on the left hand side of yFigures 1, 2 and 3 consists of a ball seat member 38 which has the same number of balls, and a similar spacing of the balls as the mounting- 32 in ball seat I8. Balls 39 oi? the driver member and balls 46 of the driven member are seated within partially spherical seats in members 32 and 38 respectively and are held in position by rivets, or screws 42 and 43 respectively, these retainers being placed so that they engage the balls slightly above their centers. The exact manner of mounting will probably best be understood by referring to Figures 9 and 10. The balls themselves, of which any reasonable number may be employed, are disposed in each lunit with ball receiving holes'45 and 46,

alternately arranged. These are positioned so as to accommodate the balls of their complementary ball retaining members for a purpose that will be later explained. T

Ball seat 38 is iixedly secured to the striker members 48 preferably being made as a part thereof. Concentrically disposed around member 48 is a sleeve 52. This sleeve is normally held against rotation by lock tit 53 which is secured to a resilient anchor pivoted at 54. Sleeve 52 serves as an anchor for the transversely disposed pins 55 and 56. These pins in turn operate within slot 58 cut in member 48, after the showing of Figure 2 particularly. To give a member that will be replaceable in case of wear I provide bushings 60, disposed between pins 55 and 56 and the walls of slot 58. Striker block 48 is counterbored at its left hand end as .viewed in the various illustrations to accommodate a tool shank 62. As a matter of convenience I have provided a key rod 64 to engage the slotted end of the tool shank and a small ball 'locking means as illustrated at 66 in Figure 3 adapted to seat within groove 68 of the tool shank so as to yieldably hold the shank in operating position.

It is very desirable to have the cam surfaces retracted or held away from engagement when the tool is not in actual driving position. To accomplish this I provide a plurality of springs as 69 and 10, which are disposed within slot 58 and are anchored against displacement within block 48 by means of anchor '|I. The opposite ends of the springs engage anchor 12 which is provided with a curved seat so as to more securely engage bushing 60 disposed about pin 55. As the springs are in compression they tend to, normally, withdraw balls 40 from engagement with balls 39.

Method of` operation In operating my tool, for instance, for wood carving a suitable chisel 'I6 is inserted in the striker end of the device. The power vis then turned on. This will revolve the ball holder I8 but will not necessarily operate the driver striker vblock 48 towards the driving end of the tool. When this condition is reached balls 40 will contact the driven balls 38 andacting on the principles of face cams ball 39 will drive ball 40 away from them. This will give the efl fective blow to chisel 16. It will follow, therefore, that the more pressure applied by the operator, the stronger will be the blow struck, up to the full limit of power available in the tool, and this without any manual operation or control other than varying the pressure supplied to housing I4, in the direction of the tool.

For use in drilling rock and the-like a suitable drill would have to be inserted in lieu of chisel 'I6 and, further, tit 53 would-then be removed as illustrated in Figure 4. The driving action yof balls 39 then result in a combined reciprocating movement to striker 48 and a slow step by step revolving action l which is so desirable when drilling round holes with a rock drill. If, for any reason, it were not desirable to use the' rotary action tit 53 would be left in place and the action would be exactly the same as when the chisel 'I6 is used.

However, when the tool is used against matevrial that it cannot drive the chisel, or drill, into any appreciable amount, means must be provided to take care of the displacement required when balls 39 are revolved, if this is not taken care of the only possible movement is to move the entire housing I4 away from the work. This is objectionable. It is under conditions such as this that the modification shown in Figure 15 should be used, as it is possible for spring 26 to take up this displacement and in so doing return as eiective work the energy absorbedby the spring. If the tool is going to be used solely for heavy hammering vas for instance riveting, drilling concrete and the like where it is impossible for the cutting bit to be driven its full extent away from the housing, and further if .the operator is willing to sacrifice the ability to vary the weight of blow,

then the maximum power blow will be delivered by the tool when the driven head I8 is close enough to the striker 48 so that balls 39 are disposed in an interlocking arrangement with balls 40 and held in this relationship by means of spring 26. This can be accomplished in a number of ways. In Figure 15 I have illustrated this modification by having the threaded portion at 96 of suiiicient length so that, by screwing up thereon, head I8 can be so advanced as to bring about this interlocking condition. It will then follow that when the driving member I8 is revolved in the usual manner it will drive the striker toward the work as far as possible and then the balance of the displacement will be taken up by driving member I8 backward against spring 2,6. This energy, however, will not belost inasmuch as a secondary effect occurs when the stored up energy in spring 26 is again released by the balls again interlocking as they must do in each half revolution.

The third possibility of using this tool is for pressed toward the driving end of the tool until 39 seat within holes 45 of carrier 38. This condition of intermeshing is maintained by providing a clip 80 which, has inwardly turned lugs 8l adapted to engage an annular groove 84 cut in theend of the device and an opposite end having similar inturned lugs 85 which are adapted to engage an annular groove 86 formed in drill bit 18.

'Ihe foregoing description and the accompanying drawings are believed to clearly disclose a preferred embodiment of my invention but it will be understood that this disclosure is merely' illustrative and that such 'changes in the invention may be made as are fairly within the scope and spirit of the following claims.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

l. The combination in a power tool with a rotary driving member having spaced annular bearings and a thrust member therebetween, and a reciprocable driven member, of holders mounted in the ends of said members, and pairs of `balls seated in the adjoining faces of said holders, whereby the rotary motion of the driving member is converted into reciprocating motion inthe driven member.

2. The combination in a power tool with a rotary driving member, a spring-retracted, reciprocable driven member, of a holder oscillatable transversely of the axis of said tool and mounted in the end of said driving member, and a fixed holder mounted in the adjoining end of said driven member, and pairs of balls seated in the adjacent faces of each holder for converting the rotary motion of the driving member into reciprocating motion in the driven member.

3. 'Ihe combination in a power tool with a rotary driving member having spaced annular bearings and a resilient thrust member therebetween, and a reciprocable driven member, of holders mounted in the ends of said members,

,- and pairs of balls seated in the adjoining faces of said holders, whereby the rotary motion of the driving member' is converted intoA reciprocating motion in the driven member.

4. The combination in a power tool with a rotary driving Y member, and a lreciprocable driven member, and pairs of balls revolvably seated insemi-spherical recesses vin the adjoining faces of each member, whereby the rotary motion of the driving member is converted-into reciprocating motion inthe driven member.

5.. The combination in a power tool with a rotary driving member, and a reciprocable,

spring retracted driven member, of an oscillatable holder mounted `in the end of said driving member, and a xed holder mounted in the adjoining end of said driven member, and pairsof balls revolvably seated in semi-spherical recesses in the adjacent faces of said holders,

whereby the rotary motion of the driving member is converted into reciprocating motion in the driven member.

6. The combination in a power tool with'a housing, a rotary driving member, and a reciprocable driven member, of holders mounted in the ends of said members, and pairs of balls revolvably seated in the adjacent faces of said holders, and guide means in said housing adapted to prevent said driven member revolving when acted upon by the driving member.

'7. The combination in a power tool with a housing, a rotary driving member, and a. reciprocable driven member, of holders mounted in each of said members, pairs of balls revolvably seated in the adjoining faces of said holders, a spring-detent having pins of varying lengths at its opposite ends for alternate use in preventing or permitting rotation of the driven member when acted upon by the driving member,

8. The combination in a power tool with a ,rotary driving member having an -end-holder and a pair of balls seated in said holder, of a driven member comprising a slotted reciprocable striker block having a pair of complementary balls, a sleeve surrounding the striker block and spaced guides mounted on'the sleeve extending through the slotted striker block, a housing enclosing said members, and a spring detent mounted inthe housing for engagement with the sleeve to hold the latter against rotation.

9. The combination in a power tool with a housing, a rotary driving member and a reciprocable driven member, of an oscillatableholder mounted on the driving member and a holder mounted on the driven member, pairs of balls seated in the adjoining faces of said holders, a housing enclosing said members, and means .mounted in the housing for engagement with the driven member to hold the latter againstrota'tion. y

l0. The combination in a power toolwith a housing, a rotary driving member, and a reciprocable, rotary driven member, Aof holders mounted inthe ends of said members, pairs of balls seated in. the adjoining faces of said holders, and a pair of spaced spring detents mounted in said housing for alternate use with said driven member wheremember.

Il. The combination in a power tool with a rotary driving member, and a reciprocable driven member, of Aa ball holder mounted in the end of said driving member, and a ball holder mounted in thev adjoining end of said driven member, and

pairs of balls revolvably seated in recesses in the adjacent faces of said holders, wherebythe rotary motion of the driving member is converted into reciprocating motion inthe driven member.

HALFORD LEMBKE. 

